Responding to Ludwig's excellent point:
The surest form of contraception is prosperity. Almost all wealthy societies are at or close to ZPG.

The second most effective form of contraception is urbanisation. People in cities have fewer kids that rural folk. Even in relatively poor places, like Mexico City, the birth rate is dropping.

The conversion of sex from primarily a reproductive activity to primarily a recreational activity in western society is, in my view, partly an unconscious biological response to the population question.

To avoid the population 'crash' scenario - which would be horrific for all species including our own - we need to increase the rate at which all societies become affluent, counter-intuitive though it may sound.

The solution is to end global poverty, not only because it is humane to do so, but also because it is about bringing our population into balance with our resources.

Thus, human demand must increase before it can manageably decrease. Recycling nutrients is one of the best ways we can do this, by raising nutritional standards for all, while reducing the environmental costs of doing so.

Your argument makes some sense Julian, but there are just simply not the resources for all of the world’s poor to reach a level of affluence at which their fertility rate drops sufficiently. Nor is there the ability for our environment to absorb the waste products.

Even with the most optimistic improvements in efficient nutrient recycling or resource usage, it sounds like an impossible task.

Then there is the timeline. We just don’t have the time to raise affluence across the third world before the population becomes too big to support. Many people think it is too big to support now, with current levels of affluence.

And perhaps most ominously of all, as previously mentioned on this thread, if we were really amazingly successful in raising standards of living, we would be facilitating high levels of population growth, perhaps at a bit of a reduced rate, until such a time that affluence became high enough for women to choose career paths rather than having large families, and for some of the other factors that lower birthrates to kick in.

By the time all of the world’s population has a standard of living high enough to engender a below-replacement birthrate, the population would be much higher, the average personal footprint on our environment and resource base would be much higher and the combination of the two would simply do us in, well and truly.

Julian, I don’t see any way out of this crisis. I think we destined to suffer an almighty population crash.

As unpalatable as it is, I think that the sooner the crash happens the better, for our species and for all others. It seems that just about anything we do will simply prolong the crash and increase its magnitude.

Oh dear, I wrote in my last post; “However, if we had the collective presence of mind, I reckon we could deal with it.” Mmmmmm, I wonder.

Hell of an issue to come to terms with

Ludwig - at the International Assn of Ag Economists, in Surfers now, I put this question to several top economists. All agree is is within our power to double food production without causing complete env devastatation. The main obstacle at the moment, they say, is the low price of food which is inhibiting the takeup of new technologies that would increase yields. There's something in this. As food prices rise, output will increase.
And, my observation, the drop in the birthrate starts to cut in at a per capita income around $US2000-3000, which is about where countries like Malaysia and Russia are today. So a society doesn't have to be super rich to slow or stop reproduction. The UN forecasts of mid-century population have been dropping for a decade or so, which suggests a general slowdown is happening.

That sounds positive Julian. But it does prompt a few more questions;

Can we both double food production and vastly increase ethanol / biodiesel production in lieu of peak oil? What will this lead to in terms of land-clearing and extinction rates?

How do the economics and practicalities look when we consider the rising price of oil, and the dependence of practically all crops other than those of subsistence farmers on oil for ploughing, seeding, fertilising, harvesting, and transporting produce?

What does it mean for many peoples who are battling to make ends meet now if food prices rise? Ok, there might be a benefit in terms of the implementation of more efficient technologies, but this would only come after price rises that, even if very moderate, would have devastating effects in many places. Prices rise as demand increases with respect to supply or as essential ingredients become more expensive. Either way, people are going to suffer big time in the first instance.

It seems to be a case of just allowing market forces to dictate the situation. Which basically means that things have to become pretty grim before significant change occurs.

I think you might be right in theory, but in practice I feel that it will, as is almost always the case, be too little too late. The tide of change seems to lag far behind both the time that we need the change to happen and the necessary magnitude.

Gee, I am not normally a hopeless pessimist. But by crikey, this time the issue seems too hard to put on an optimistic face